Police collaborated with Temple University researchers to assign 200 officers to foot patrols in the city’s highest-volume crime areas and analyze the results. Temple's study, which covered three months, showed a 22 percent drop in crime in areas covered by the foot patrols. Jerry Ratcliffe, a professor of criminal justice at Temple, and his colleagues analyzed and mapped crime data for 2006, 2007, and 2008, revealing clusters of crime within just a few blocks. "Philadelphia's got really small neighborhoods, and I think many people's lives revolve around a few streets," Ratcliffe said. "When something happens, everyone knows about it, and you can't let people in that neighborhood know you let something slide." The Temple study also found reduced crime in many of the areas adjoining the foot patrols. Crime rose slightly in some bordering areas, but the crime reduction in the patrol areas outweighed those increases in most cases, Ratcliffe said.